Buying a roof sealant is easy that sounds so simple until you find yourself standing in the aisle and wondering if one tube will do, or whether it would run out halfway through repairing your leak. Coverage is a reflection of the situation you are attempting to treat: applying sealant along a narrow joint uses far less than filling in a wider crack or patch.
What you are seeking to seal
These are pretty typical DIY jobs:
Beaded seam beads (around flashing, trims, roof edges)
Small cracks/holes (spot repairs)
Patches (covering a fissure in felt/flat roof)
Quick Rule of Thumb
An easy way to estimate just how long a standard cartridge (normally 300ml) will last:
5mm beads: 10^ metres, mid-way into the full string
10mm bead: around 3.5m
Spread in patches or coverage drops very rapidly. An individual cartridge will likely only be enough to cover a small section once it is applied thickly enough that it becomes waterproof.
Add a little extra
Always allow for:
Irregular surfaces (felt, mortar, rough flashing)
Loss (priming, overcoat and blend-back; rework an area)
If you are taping a corner or seam.
A nice rule of thumb is an extra tube for small jobs, or 10-20% more than what’s needed on larger repairs. For Roof sealant products, visit a site like www.ct1.com/product-applications/ct1-the-ultimate-roof-sealant
Don’t forget the prep
Sealant will adhere very poorly to damp, soiled or mossy surfaces. A clean dry surface is often more important than the perfect product.
